Changes LZ4F_compressBound() definition using NULL prefsPtr to cover worst case instead of default.

3 files changed, 6 insertions, 5 deletions

diff --git a/lib/lz4frame.c b/lib/lz4frame.c
index 31cf9a5..8d4c029 100644
--- a/lib/lz4frame.c
+++ b/lib/lz4frame.c
@@ -472,12 +472,13 @@ size_t LZ4F_compressBegin(LZ4F_compressionContext_t compressionContext, void* ds
 
 /* LZ4F_compressBound() : gives the size of Dst buffer given a srcSize to handle worst case situations.
 *                        The LZ4F_frameInfo_t structure is optional :
-*                        you can provide NULL as argument, all preferences will then be set to default.
+*                        you can provide NULL as argument, preferences will then be set to cover worst case situations.
 * */
 size_t LZ4F_compressBound(size_t srcSize, const LZ4F_preferences_t* preferencesPtr)
 {
     LZ4F_preferences_t prefsNull;
     memset(&prefsNull, 0, sizeof(prefsNull));
+    prefsNull.frameInfo.contentChecksumFlag = contentChecksumEnabled;   /* worst case */
     {
         const LZ4F_preferences_t* prefsPtr = (preferencesPtr==NULL) ? &prefsNull : preferencesPtr;
         blockSizeID_t bid = prefsPtr->frameInfo.blockSizeID;
diff --git a/lib/lz4frame.h b/lib/lz4frame.h
index e5435cd..f22ef00 100644
--- a/lib/lz4frame.h
+++ b/lib/lz4frame.h
@@ -141,9 +141,9 @@ size_t LZ4F_compressBegin(LZ4F_compressionContext_t cctx, void* dstBuffer, size_
 size_t LZ4F_compressBound(size_t srcSize, const LZ4F_preferences_t* prefsPtr);
 /* LZ4F_compressBound() :
  * Provides the minimum size of Dst buffer given srcSize to handle worst case situations.
- * prefsPtr is optional : you can provide NULL as argument, all preferences will then be set to default.
- * Note that different preferences will produce different results.
- * This function doesn't include frame termination cost (4 bytes, or 8 is frame checksum is enabled)
+ * Different preferences can produce different results.
+ * prefsPtr is optional : you can provide NULL as argument, all preferences will then be set to cover worst case.
+ * This function includes frame termination cost (4 bytes, or 8 is frame checksum is enabled)
  */
 
 size_t LZ4F_compressUpdate(LZ4F_compressionContext_t cctx, void* dstBuffer, size_t dstMaxSize, const void* srcBuffer, size_t srcSize, const LZ4F_compressOptions_t* cOptPtr);
diff --git a/programs/lz4io.c b/programs/lz4io.c
index 9287979..db34747 100644
--- a/programs/lz4io.c
+++ b/programs/lz4io.c
@@ -421,7 +421,7 @@ static cRess_t LZ4IO_createCResources(void)
     /* Allocate Memory */
     ress.srcBuffer = malloc(blockSize);
     ress.srcBufferSize = blockSize;
-    ress.dstBufferSize = LZ4F_compressBound(blockSize, NULL);   /* risk : real prefs may cost more */
+    ress.dstBufferSize = LZ4F_compressBound(blockSize, NULL);   /* cover worst case */
     ress.dstBuffer = malloc(ress.dstBufferSize);
     if (!ress.srcBuffer || !ress.dstBuffer) EXM_THROW(31, "Allocation error : not enough memory");